Reichenau Island lies in Lake Constance in southern Germany, at approximately 47°42′N 9°4′E / 47.7°N 9.067°E. It lies between the Gnadensee and the Untersee, almost due west of the city of Konstanz. The island is connected to the mainland by a causeway that was completed in 1838. Nevertheless, the island is separated from it by a 10-meter-wide Bruckgraben, which is spanned by a low road bridge that allows passage of ordinary boats but not of sailboats through its 95-meter course. The highest elevation on the island, the Hochwart, reaches 438.7 meters, or 43 meters above the lake surface.